Information systems supporting mobile units in computing location are known. The mobile unit user determines its location utilizing a location determining mechanism containing data bases of geographical information, for example, roads, rivers, landmarks, and so forth. Then the mobile unit user sends this information to a control base. The present systems provide the mobile unit with a comprehensive listing of communication systems available.
As a mobile unit user moves from a geographical area supported by one communication system to another geographical area supported by another communication system, it becomes desirable to provide the mobile unit user with the capability of determining the identity of the most readily available communication system without undue time expenditure.
Accordingly, there exists a need for a mobile unit user interface that minimizes the time required to select a valid adjacent communication system when the mobile unit user moves from a geographical area supported by one communication system to a geographical area supported by another communication system.